How to check whether netconnection is available or not in iPhone?
https://stackoverflow.com/questions/6371887
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28-10-2019 - |
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I have an application in which I have login form which username and password textfields. when user enter his/her username and password and click on the submit button, then it will go to server API database and check whether user is valid or not. If connection is not their values are checked in SQLite database.
If in SQLite database if users username and password are validated then the user is allowed to enter into the application otherwise he would have to register. I tried the following code but now I am confused where should have to put my code.
I have check both server connection and SQLite connection. My answer is if user login again and again then username and password should always check first from server not in SQLite database. If server is OFF then username and password should check from SQLite database.
This is my code:
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(checkNetworkStatus:) name:kReachabilityChangedNotification object:nil];
internetReachable = [[Reachability reachabilityForInternetConnection] retain];
[internetReachable startNotifier];
// check if a pathway to a random host exists
hostReachable = [[Reachability reachabilityWithHostName: @"www.apple.com"] retain];
[hostReachable startNotifier];
The callback is as follows;
- (void) checkNetworkStatus:(NSNotification *)notice
{
// called after network status changes
NetworkStatus internetStatus = [internetReachable currentReachabilityStatus];
switch (internetStatus)
{
case NotReachable:
{
break;
}
case ReachableViaWiFi:
{
break;
}
case ReachableViaWWAN:
{
break;
}
}
NetworkStatus hostStatus = [hostReachable currentReachabilityStatus];
switch (hostStatus)
{
case NotReachable:
{
break;
}
case ReachableViaWiFi:
{
break;
}
case ReachableViaWWAN:
{
break;
}
}
}
This is my api controller, where I am fetching values from my API server and inserting values in SQLite database:
//
// apicontroller.m
// apitest
//
// Created by raji.nair on 6/10/11.
// Copyright 2011 __MyCompanyName__. All rights reserved.
//
#import "apicontroller.h"
#import "Result.h"
#import "global.h"
#import <sqlite3.h>
#define DATABASE_NAME @"journey.sqlite"
#define DATABASE_TITLE @"journey"
@implementation apicontroller
@synthesize txtUserName;
@synthesize txtPassword;
@synthesize txtfirstName;
@synthesize txtlast;
@synthesize txtEmail;
@synthesize webData;
- (NSString *) getWritableDBPath {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES);
NSString *documentsDir = [paths objectAtIndex:0];
return [documentsDir stringByAppendingPathComponent:DATABASE_NAME];
}
-(void)createEditableCopyOfDatabaseIfNeeded
{
// Testing for existence
BOOL success;
NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:DATABASE_NAME];
NSLog(@"%@",writableDBPath);
success = [fileManager fileExistsAtPath:writableDBPath];
if (success)
return;
// The writable database does not exist, so copy the default to
// the appropriate location.
NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath]
stringByAppendingPathComponent:DATABASE_NAME];
success = [fileManager copyItemAtPath:defaultDBPath
toPath:writableDBPath
error:&error];
if(!success)
{
NSAssert1(0,@"Failed to create writable database file with Message : '%@'.",
[error localizedDescription]);
}
}
-(void)sendRequest
{
UIDevice *device = [UIDevice currentDevice];
NSString *udid = [device uniqueIdentifier];
NSString *sysname = [device systemName];
NSString *sysver = [device systemVersion];
NSString *model = [device model];
NSLog(@"idis:%@",[device uniqueIdentifier]);
NSLog(@"system nameis :%@",[device systemName]);
NSLog(@"System version is:%@",[device systemVersion]);
NSLog(@"System model is:%@",[device model]);
NSLog(@"device orientation is:%d",[device orientation]);
NSString *post = [NSString stringWithFormat:@"Loginkey=%@&Password=%@&DeviceCode=%@&Firmware=%@&IMEI=%@",txtUserName.text,txtPassword.text,model,sysver,udid];
NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];
NSLog(@"%@",postLength);
NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
[request setURL:[NSURL URLWithString:@"http://192.168.0.68:91/JourneyMapperAPI?RequestType=Login"]];
[request setHTTPMethod:@"POST"];
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setHTTPBody:postData];
NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
if (theConnection) {
webData = [[NSMutableData data] retain];
NSLog(@"%@",webData);
}
else
{
}
}
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
[webData setLength: 0];
}
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[webData appendData:data];
}
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
[connection release];
[webData release];
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSString *loginStatus = [[NSString alloc] initWithBytes: [webData mutableBytes] length:[webData length] encoding:NSUTF8StringEncoding];
NSLog(@"%@",loginStatus);
NSString *json_string = [[NSString alloc] initWithData:webData encoding:NSUTF8StringEncoding];
NSDictionary *result = [json_string JSONValue];
NSArray *values = [result objectForKey:@"Result"];
NSMutableArray *results = [[NSMutableArray alloc] init];
for (int index = 0; index<[values count]; index++) {
NSMutableDictionary * value = [values objectAtIndex:index];
Result * result = [[Result alloc] init];
result.UserID = [value objectForKey:@"UserId"];
result.FirstName = [value objectForKey:@"FirstName"];
result.LastName =[value objectForKey:@"LastName"];
result.Email =[value objectForKey:@"Email"];
result.ProfileImage =[value objectForKey:@"ProfileImage"];
result.ThumbnailImage =[value objectForKey:@"ThumbnailImage"];
result.DeviceInfoId =[value objectForKey:@"DeviceInfoId"];
NSLog(@"%@",result.UserID);
[results addObject:result];
[result release];
}
for (int index = 0; index<[results count]; index++) {
Result * result = [results objectAtIndex:index];
//save the object variables to database here
[self createEditableCopyOfDatabaseIfNeeded];
NSString *filePath = [self getWritableDBPath];
sqlite3 *database;
if(sqlite3_open([filePath UTF8String], &database) == SQLITE_OK) {
NSDate *dt = [NSDate date]; //get current date
NSString *timestamp = [dt description];
NSString *journeyid = [NSString stringWithFormat:@"%@_%@_%@", result.UserID, result.DeviceInfoId, timestamp];
const char *sqlStatement = "insert into UserInformation(UserID,DeviceId,FirstName,Email,JourneyID) VALUES (?,?,?,?,?)";
sqlite3_stmt *compiledStatement;
if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) {
sqlite3_bind_text( compiledStatement, 1, [result.UserID UTF8String],-1,SQLITE_TRANSIENT);
sqlite3_bind_text(compiledStatement, 2, [result.DeviceInfoId UTF8String],-1,SQLITE_TRANSIENT);
sqlite3_bind_text (compiledStatement, 3, [result.FirstName UTF8String],-1,SQLITE_TRANSIENT);
sqlite3_bind_text (compiledStatement, 4, [result.Email UTF8String],-1,SQLITE_TRANSIENT);
sqlite3_bind_text(compiledStatement, 5, [journeyid UTF8String], -1, SQLITE_TRANSIENT);
}
if(sqlite3_step(compiledStatement) != SQLITE_DONE ) {
NSLog( @"Save Error: %s", sqlite3_errmsg(database) );
}
else {
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"UIAlertView" message:@"Record added" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
[alert release];
alert = nil;
}
sqlite3_finalize(compiledStatement);
}
sqlite3_close(database);
}
[loginStatus release];
[connection release];
[webData release];
}
-(IBAction)click:(id)sender
{
[self sendRequest];
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
[txtfirstName resignFirstResponder];
[txtlast resignFirstResponder];
[txtUserName resignFirstResponder];
[txtPassword resignFirstResponder];
[txtEmail resignFirstResponder];
}
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
[super viewDidLoad];
//[self sendRequest];
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc. that aren't in use.
}
- (void)viewDidUnload {
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)dealloc {
[super dealloc];
}
@end
This is class where I am creating nsstring variables of my json object:
//
// Result.h
// apitest
//
// Created by pradeep.yadav on 6/14/11.
// Copyright 2011 __MyCompanyName__. All rights reserved.
//
#import <Foundation/Foundation.h>
//TokenID":"Vao13gifem","isError":false,"ErrorMessage":"","Result":[{"UserId":"153","FirstName":"Rocky","LastName":"Yadav","Email":"rocky@itg.com","ProfileImage":null,"ThumbnailImage":null,"DeviceInfoId":"12"}],"ErrorCode":900}
//Terminating in response to SpringBoard's termination.
@interface Result : NSObject {
NSString * UserID;
NSString *FirstName;
NSString *LastName;
NSString *Email;
NSString *ProfileImage;
NSString *ThumbnailImage;
NSString *DeviceInfoId;
}
@property (nonatomic,retain) NSString *UserID;
@property (nonatomic,retain) NSString *FirstName;
@property (nonatomic,retain) NSString *LastName;
@property (nonatomic,retain) NSString *Email;
@property (nonatomic,retain) NSString *ProfileImage;
@property (nonatomic,retain) NSString *ThumbnailImage;
@property (nonatomic,retain) NSString *DeviceInfoId;
@end
//
// Result.m
// apitest
//
// Created by pradeep.yadav on 6/14/11.
// Copyright 2011 __MyCompanyName__. All rights reserved.
//
#import "Result.h"
@implementation Result
@synthesize UserID;
@synthesize FirstName;
@synthesize LastName;
@synthesize Email;
@synthesize ProfileImage;
@synthesize ThumbnailImage;
@synthesize DeviceInfoId;
- (void)dealloc {
[super dealloc];
[UserID release];
[FirstName release];
[LastName release];
[Email release];
[ProfileImage release];
[ThumbnailImage release];
[DeviceInfoId release];
}
@end
If my server API that is available through netconnection is not available then my username and password values should be fetched and validated from database.
Solution
NSMutableURLRequest * serviceRequest = [NSMutableURLRequest requestWithURL:serviceUrl];
[serviceRequest setValue:@"text/xml" forHTTPHeaderField:@"Content-type"];
[serviceRequest setHTTPMethod:@"POST"];
[serviceRequest setHTTPBody:[xmlString dataUsingEncoding:NSUTF8StringEncoding]];
NSData *responseData;
NSURLResponse * serviceResponse;
NSError * serviceError;
responseData = [NSURLConnection sendSynchronousRequest:serviceRequest returningResponse:&serviceResponse error:&serviceError];
NSString *resp=[[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSLog(@"RETRIEVING:%@",resp);
if(responseData != NULL)
{
//connection exist
}
else
{
//Connection doesn't exist
}
OTHER TIPS
Late to the show here, but the best solution for checking this is with Reachability. Reachability was written by Apple as "sample code", but is by far the most complete way to gracefully handle network status. Check out the Reachability Guide.
Here is some information in regards to how to use Reachability: Reachability Guide for iOS 4
I have reviewed your question. I think you should follow below flow:
User will enter "Username" and "Password" in login form.
Then first check in local database.
If user exists then user can direct login and access the app.
If user not exists then check it's credential from live server.
If user is valid, then make entry of Username & Password into local database. So that, next time he can login direct.
If user is not valid then simply give message for access denied.
Now, for checking for net connection: For that, take one web-view (web-view will be invisible). Then open simple website like "http://www.google.com" and also implement web-view delegate method.
in web-view delegate method:
- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error{
[self connectionFailed:error];
}
below is the "connectionFailed" function:
-(void)connectionFailed:(NSError *)error{
if ([error code] == -999) {
//show error alert, etc.
//NSLog(@"-999 Detected, Do Nothing");
//NSLog([error localizedDescription]);
}
else if([error code] == -1009 || [[error localizedDescription] isEqualToString:@"no Internet connection"]){
[self hideLoading];
[connectionView loadHTMLString:@"<body bgcolor=#58637C><br><br><br><br><font size=5 color=white>Please turn on your Internet connection to access this application.</font></body>" baseURL:nil];
[connectionView setFrame:CGRectMake(0.0, 0.0, 320.0, 431.0)];
[self.view addSubview:connectionView];
}
else if([error code] == -1001 || [[error localizedDescription] isEqualToString:@"timed out"]){
[self hideLoading];
[connectionView loadHTMLString:@"<body bgcolor=#58637C><br><br><br><br><font size=5 color=white>Request Timed Out.</font></body>" baseURL:nil];
[connectionView setFrame:CGRectMake(0.0, 0.0, 320.0, 431.0)];
[self.view addSubview:connectionView];
}
else if (error != NULL) {
[self hideLoading];
[connectionView loadHTMLString:@"<body bgcolor=#58637C><br><br><br><br><font size=5 color=white>Error loading page, Please try again later.</font></body>" baseURL:nil];
[connectionView setFrame:CGRectMake(0.0, 0.0, 320.0, 431.0)];
[self.view addSubview:connectionView];
}
else{
}
}
Here, connectionView view is another web-view. You can simply replace the code with UIAlerView with proper message.
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